#include <iostream>

/**
 * A union is a data format that can hold different data types but only one type at a time.
*/

union one4all{
    int int_val;
    long long_val;
    double double_val;
};

using namespace std;

int main(){
    one4all pail;
    pail.int_val = 16;
    cout<<pail.double_val<<endl;
    cout<<pail.int_val<<endl;;
    return 0;
}